| Exam Board | CAIE |
|---|---|
| Module | M1 (Mechanics 1) |
| Year | 2024 |
| Session | November |
| Marks | 5 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Work done and energy |
| Type | Energy method - smooth inclined plane (no resistance) |
| Difficulty | Moderate -0.8 Part (a) is a direct application of conservation of energy (PE = KE) requiring only one equation and basic algebra. Part (b) adds friction using the work-energy theorem but remains a straightforward calculation with given values. Both parts are standard textbook exercises with no problem-solving insight required, making this easier than average for A-level. |
| Spec | 6.02i Conservation of energy: mechanical energy principle |
| Answer | Marks |
|---|---|
| 2(a) | 1 |
| Answer | Marks | Guidance |
|---|---|---|
| PE =7.5g12.5 [= 937.5] | *B1 | Either correct. |
| v=15.8ms−1 | DB1 | 5 10. |
| Answer | Marks | Guidance |
|---|---|---|
| Question | Answer | Marks |
| Answer | Marks | Guidance |
|---|---|---|
| 2(b) | KE =0.57.582 [= 240] | |
| B | B1 | |
| 7.5g12.5=0.57.582 +F25 | M1 | Attempt at work energy equation; 3 terms; dimensionally correct; |
| Answer | Marks |
|---|---|
| F =27.9 | A1 |
| Answer | Marks | Guidance |
|---|---|---|
| 82 =02 +2a25a=1.28 | B1 | Finding the correct acceleration down the plane. |
| Answer | Marks | Guidance |
|---|---|---|
| 25 | M1 | Newton’s second law parallel to the plane; allow sign errors and |
| Answer | Marks |
|---|---|
| F =27.9 | A1 |
| Answer | Marks | Guidance |
|---|---|---|
| Question | Answer | Marks |
Question 2:
--- 2(a) ---
2(a) | 1
KE = 7.5v2
2
PE =7.5g12.5 [= 937.5] | *B1 | Either correct.
v=15.8ms−1 | DB1 | 5 10.
12.5
SC B1 for v2 =02 +2(gsin) v=15.8 (or with cos).
sin
B0 for v2 =02 +2g12.5v=15.8 or correct answer with no
working.
2
Question | Answer | Marks | Guidance
--- 2(b) ---
2(b) | KE =0.57.582 [= 240]
B | B1
7.5g12.5=0.57.582 +F25 | M1 | Attempt at work energy equation; 3 terms; dimensionally correct;
allow sign errors.
F =27.9 | A1
ALTERNATIVE FOR 2(b)
82 =02 +2a25a=1.28 | B1 | Finding the correct acceleration down the plane.
12.5
7.5g −F =7.5a
25 | M1 | Newton’s second law parallel to the plane; allow sign errors and
sin/cos mix on the weight component; dimensionally correct.
Allow with their a, or just a .
F =27.9 | A1
3
Question | Answer | Marks | Guidance
\includegraphics{figure_2}
A particle of mass $7.5$ kg, starting from rest at $A$, slides down an inclined plane $AB$. The point $B$ is $12.5$ metres vertically below the level of $A$, as shown in the diagram.
\begin{enumerate}[label=(\alph*)]
\item Given that the plane is smooth, use an energy method to find the speed of the particle at $B$. [2]
\item It is given instead that the plane is rough and the particle reaches $B$ with a speed of $8 \text{ ms}^{-1}$. The plane is $25$ m long and the constant frictional force has magnitude $F$ N.
Find the value of $F$. [3]
\end{enumerate}
\hfill \mbox{\textit{CAIE M1 2024 Q2 [5]}}